Virtual Radio Map Constructing Method and Device Using the Same

1. A virtual radio map constructing method, comprising: converting first and second received signal strengths (RSS values) obtained from two access points adjacent to each of a plurality of access points disposed in a target space into first and second RSS values of a linear unit; respectively dividing first and second distances between an access point of the plurality of access points and the two access points adjacent thereto in an exponential interval, and respectively dividing the converted first and second RSS values in the exponential interval; generating a plurality of virtual training points in the target space by using a plurality of points divided in the exponential interval between the access point and the two adjacent access points, and respectively obtaining RSS values of the plurality of virtual training points by using first and second RSS values corresponding to the virtual training point; and respectively obtaining RSS values of reference points by using RSS values of at least one virtual training points existing within a reference distance from each of the reference points arranged in an equal interval in the target space.

2. The virtual radio map constructing method of claim 1 , further comprising: constructing a radio map consisting of a plurality of RSS values per the reference point by separately obtaining the RSS values of the reference points based on each of the plurality of access points, wherein the radio map is respectively constructed for each of a plurality of target spaces.

3. The virtual radio map constructing method of claim 2 , further comprising: radio-positioning a location of a random node by comparing the plurality of RSS values obtained between a random node in the target space and the plurality of access points with RSS values stored in the radio map.

4. The virtual radio map constructing method of claim 1 , wherein the dividing in the exponential interval uses the following equation: D ⁡ ( t ) = a ⁡ ( L a ) t / T wherein D(t) denotes a t-th divided distance or a RSS value, a denotes an initial starting value used for the dividing, L denotes a final target value used for the dividing, and T denotes a total divided number, t={1, . . . , T}.

5. The virtual radio map constructing method of claim 1 , wherein the obtaining of each of the RSS values of the virtual training points uses the following equation: VTP ⁡ ( x i , y j ) = α x i ⁢ β y j ⁢ max ⁡ ( α x i , β y j ) 2 ⁢ ( α x i 2 + β y j 2 ) wherein VTP (x i , y i ) denotes a RSS value of a virtual training point (VTP) generated at point (x i , y i ) in the target space, and α x i and β y i denote a first RSS value and a second RSS value corresponding to point (x i , y i ).

6. The virtual radio map constructing method of claim 1 , wherein the obtaining of each of the RSS values of the reference points obtains an average of the RSS values of the at least one virtual training points existing within the reference distance from the reference point as a RSS value of the reference point.

7. A virtual radio map construction device, comprising: a storage; a linear unit converter configured to convert first and second received signal strengths (RSS values) obtained from two access points adjacent to each of a plurality of access points disposed in a target space into first and second RSS values of a linear unit; an exponential interval divider configured to respectively divide first and second distances between an access point of the plurality of access points and the two access points adjacent thereto in an exponential interval, and respectively dividing the converted first and second RSS values in the exponential interval; a virtual point generator configured to generate a plurality of virtual training points in the target space by using a plurality of points divided in the exponential interval between the access point and the two adjacent access points; a virtual point calculator configured to respectively obtain RSS values of the plurality of virtual training points by using first and second RSS values corresponding to the virtual training point; and a reference point calculator configured to respectively obtain RSS values of reference points by using RSS values of at least one virtual training points existing within a reference distance from each of the reference points arranged in an equal interval in the target space.

8. The virtual radio map construction device of claim 7 , further comprising: a radio map constructor configured to construct a radio map consisting of a plurality of RSS values per the reference point by separately obtaining the RSS values of the reference points based on each of the plurality of access points, wherein the radio map is respectively constructed for each of a plurality of target spaces.

9. The virtual radio map construction device of claim 8 , further comprising: a Radio-positioning portion configured to perform radio-positioning of a location of the random node by comparing the plurality of RSS values obtained between a random node in the target space and the plurality of access points with RSS values stored in the radio map.

10. The virtual radio map construction device of claim 7 , wherein the exponential interval divider uses the following equation when it performs the dividing in the exponential interval: D ⁡ ( t ) = a ⁡ ( L a ) t / T wherein D(t) denotes a t-th divided distance or a RSS value, a denotes an initial starting value used for the dividing, L denotes a final target value used for the dividing, and T denotes a total divided number, t={1, . . . , T}.

11. The virtual radio map construction device of claim 7 , wherein the virtual point calculator obtains each of the RSS values of the virtual training points through the following equation: VTP ⁡ ( x i , y j ) = α x i ⁢ β y j ⁢ max ⁡ ( α x i , β y j ) 2 ⁢ ( α x i 2 + β y j 2 ) wherein VTP (x i , y i ) denotes a RSS value of a virtual training point (VTP) generated at point (x i , y i ) in the target space, and α x i and β y i denote a first RSS value and a second RSS value corresponding to point (x i , y i ).

12. The virtual radio map construction device of claim 7 , wherein the reference point calculator obtains an average of the RSS values of the at least one virtual training points existing within the reference distance from the reference point as a RSS value of the reference point.